1. Field of the Disclosed Technology
Generally, the field of the present disclosed technology is wavelength locking diode lasers. More particularly, the present disclosed technology relates to the wavelength locking diode lasers with fiber Bragg gratings.
2. Background
There are several on-chip wavelength locking methods for semiconductor lasers, such as built-in diffraction gratings providing distributed feedback or forming distributed Bragg gratings. Similarly, surface and volume grating have been used to wavelength-lock multiple semiconductor lasers in an external cavity configuration. Surface grating wavelength-locking techniques tend to be highly sensitive to environmental changes. For example, volume gratings have finite absorption in the glass due to impurities introduced for photo-sensitizing purposes which leads to self-heating. As a result, emission wavelength shifts due to glass heating. The amount of heating becomes more significant at larger powers, for example, over 200 W, impinges on the gratings, or as power settings change. As grating temperature increases, the associated Bragg resonance wavelength shifts, making it unwieldy in applications demanding tight center wavelength tolerance. Accordingly, a need remains for wavelength selective methods and devices without these and other attendant drawbacks.